Review: Yeti SB4.5c

As soon as Yeti Cycles unleashed the vanguard of its all-new 'Switch Infinity' bikes, the SB5c and SB6c–both with 650b wheels–one question echoed around the mountain-bike world: "When is Yeti going to introduce a 29er with the new Switch Infinity suspension platform?"

Though company riders had already been testing prototypes of the new 29er for almost a year at that point, it wasn't until late last summer that Yeti introduced the wildly anticipated new model. We'd previously spent a couple of weeks on the SB4.5c during an overseas bikepacking mission, but we'd had to run higher pressures in the shock, fork and tires to compensate for the extra weight of our saddlebags. So we could hardly wait to test the bike under everyday loads and experiment with its two different shock options: an 'XC tune' and a 'trail tune.'

All of our testers were blown away by how well the SB4.5c climbed up steep, technical terrain, its 29-inch wheels decimating trail obstacles regardless of which shock was being employed. The XC tune rode higher in the travel and felt firmer under hard pedaling, but some riders noticed a slight increase in chatter over our test track's bony root sections. The trail-tuned shock was more plush across the board but still pedaled incredibly well, and when pointed downhill it really unharnessed the Switch Infinity platform's suppleness through bigger bumps.

"Given my druthers, I'd opt for the trail tune, and if I really needed to kick some XC courses to pieces I'd just put a little more air in the shock," wrote one tester.

For a bike that so clearly excels at climbing, the SB4.5c felt incredibly balanced, its longish toptube and sensibly slack 67.4-degree head angle instilling confidence on challenging descents. Describing the ideal buyer as "Shred Schralperson," one tester wrote, "It's just so damn versatile, so damn fun."

Though the build we tested costs $6,900, the full-carbon frame comes with some impressive parts, including a SRAM X01 drivetrain, SRAM Guide RSC brakes, a RockShox Reverb dropper post and lightweight-but-stiff DT Swiss XM401 wheels. It's a big investment, but one that will make life markedly easier for riders with brutal backyard climbs.

Q&A with Chris Conroy, President, Yeti Cycles

Before this year's test models rolled into our barn, we had questions about them—some of the same questions that you might be asking yourself when you start poking around at a new bike. Or maybe we're just OCD. Either way, we sent in some questions to Chris Conroy, Yeti's president. Here's what Conroy had to say about Yeti's new 29er, the SB4.5c.
—Vernon Felton, Bible of Bike Tests Moderator

VERNON FELTON: When you guys were designing the SB4.5c, who were you thinking of as the ideal kind of rider?CHRIS CONROY: The riders we had in mind fit into two distinct camps–the first is crazy about efficiency, climbing and 29ers, and the second rider is more of a 29er trail-bike guy. That's why we offer the bike with two different shock tunes. Our cross-country shock tune is aimed at the first rider–it's stiffer on the front end and firmer throughout the stroke. You feel the trail more. It has a racier feel. Our trail tune essentially mimics our SB5c: It has a great pedaling platform, but maintains great small bump compliance. The middle and end of the stroke are controlled, yet fairly plush (for a 4.5-inch travel bike).

VF: Are there conditions in which you feel this bike really excels and, if so, what specific design attributes of the bike make that so?CC: One of the things you can feel immediately is the overall stiffness of the frame. We achieved that with the larger tube shapes, a 148-millimeter Boost rear end and the layup of the frame. The stiffer frame, combined with the two distinct tunes gives the bike an incredible amount of range.

VF: Are there any aspects of the frame design that you guys are particularly proud of? If so, what are they and why?CC: There are several things on the frame we like–details mostly. The internally-routed cables give the bike a clean look. As on all of our models, the rubber bash guards on the downtube and rear triangle keep the frame protected and quiet. The geometry is classic Yeti–long, slack and with a relatively low bottom bracket. Everyone seems to be making bikes that way now, but we've done it for nearly a decade.

VF: Component spec can be tough to nail–what were you guys aiming for with the spec on this bike and how did you achieve it?CC: Component spec always leads to heated debates at Yeti. In the end, we ask ourselves, would we ride that spec? If we don't all answer "Yes,” we keep working on it until we agree.

VF: Are there any details/features on this bike that you think are particularly critical to its performance that might be easily overlooked by riders at first glance?CC: The core of the bike is the Switch Infinity system. I'm not sure consumers would overlook it, but it's what differentiates how our bikes ride.

VF: Why did you choose to go with the Boost 148 rear-end spacing?CC: Stiffness and clearance. Boost allows us to run thicker chain stays, this adds to the rear end stiffness and durability of the frame.

VF: If someone is looking at the SB4.5c, they are probably also considering the SB5–which kind of rider/riding is better suited to the SB4.5c?CC: That's a good question and unfortunately, the answer is "depends." A lot of it comes down to feel, riding preference and terrain. Some will gravitate to the SB4.5c simply because it has 29er wheels and they are committed to 29ers. I think nearly anyone who rides it will like it, regardless of wheel preference.